Optimization of industrially defatted flaxseed meal fibre digestion to enhance production of commercial-grade protein isolates

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The current high demand for plant proteins is driven by consumer awareness for healthy diets that are rich in essential amino acids but devoid of saturated or trans fats. Plant proteins not only meet these consumer expectations in terms of health benefits but are also cheaper than mainstream animal proteins. Flaxseed is an important food crop that is widely grown in the Canadian prairies. Current industrial flaxseed processing produces the highly valued omega 3-rich oil and a partially defatted high quality protein-rich meal. However, there is currently little food use for the flaxseed meal, which is normally sold as an animal feed or as a nitrogen source to fertilize farm lands. Shape Foods produces cold pressed edible flaxseed oil and the extruded partially defatted flaxseed meal by-product of this process offers the potential for a flaxseed protein isolate raw material. However, commercial protein isolate production from flaxseed meal does not exist because the high gum content in the defatted meal reduces yield and protein quality during extraction. Therefore, the main goal of the proposed work is to develop a novel method that breaks down the flaxseed meal gum such that the high viscosity that develops during aqueous protein extraction is nullified to enhance protein isolation and functionality. The proposed methods will produce protein isolates with >90% (dry weight basis) protein content, which is the benchmark for the commercial proteins. The specific goals are to: 1) Develop a flaxseed fibre (gum) digestion method using various carbohydrases; 2) Use the gum-depleted material for alkaline protein extraction followed by acid-induced protein precipitation; 3) Use the gum-depleted material for alkaline protein extraction followed by membrane ultrafiltration to produce a protein isolate; 4) Determine the physicochemical and functional properties of the protein isolates to ensure relevance as a food ingredient. The outcome of this proposed work will enhance value-added utilization of flaxseed with high economic returns to farmers, seed processors and food manufacturers.